36 Annals Entomological Society of America [Vol. XV, 



parameres. In contrast to the loss of the chitinous parts in the 

 genitalia proper the pallium is strengthened by two distinct 

 plates, separated by a median groove. 



In Acrydiiim and Paratettix the rami are absent and the 

 pseudosternite is more slender with a much smaller median 

 process, but the pallial structures are more complex than in 

 Tettigidea, there being between the pallial plates a pair of 

 slender bars, each terminating in front in an upcurved hook, 

 which probably has some function in copulation. 



Phasmoidea. 



In the stick-insects and their allies the terminal abdominal 

 terga of the males are all well developed and the 10th tends to 

 replace the supra-anal plate, which is often vestigial or obsolete. 

 In Timema californiciim Scudd. (teste Crampton, 1, c, PI. 5, 

 Figs. 53, 65) the latter is distinct and only partly overlapped by 

 the 10th tergum; in Diapheromera femorata Say it is a small and 

 membranous lobe, while in Anisomorpha biiprestoides Stoll. 

 (PL VIII, Fig. 71), it is wholly absent. The paraprocts are well 

 developed in Timema, of fair size in Anisomorpha, rather small 

 in Diapheromera. In these genera they are little, if at all, 

 chitinized, but, according to Chopard ('20), who examined a 

 large number of forms, they are commonly chitinized except on 

 their mesal surfaces. The cerci are short, unsegmented and 

 often modified as claspers {Diapheromera). The sternal region 

 of the terminal segments preserves its primitive horizontal 

 position, that of the 9th and 10th being in about the same plane, 

 so that the genitalia are ventral in position, as in the Der- 

 maptera, not terminal as in the Orthoptera, Blattoidea, etc. 

 The 9th sternum is commonly divided into two parts, a proximal 

 plate, usually short, and a distal plate, which is a more or 

 less free flap, or "hypandrium, " covering the genitalia. As in 

 the Acridoidea and Ephemerida the proximal plate is probably 

 the true sternite, the distal plate the united coxites. There 

 are no true styli. In Timema and Anisomorpha the 9th sternum 

 shows its more primitive form, in that it is broadly connected 

 with the tergum, both basally and laterally, but in Diapheromera 

 and many other genera the sternite forms a short stalk, bearing 

 the perfectly free hypandrium, which forms a cup-like receptacle 

 for the genitalia. In such forms the posterior and greater part 

 of the sternal area is uncovered by any part of the true sternum. 



